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#1840 by moreno7798 on 23 Sep, 2017 22:23
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How in the world did you get that take away (value of peer review) from my post?
I really don't think there would be any value in me doing that. For starters, if you go back to when EW's papers were released, you will find others who went into much more detail than me proposing potential error sources.I for one would like to see meberbs publish his assertions on his interpretation of Dr. Harold White's papers. I'm guessing getting past the peer review process would be a better way to be vindicated than getting into endless argument loops here. Maybe he could score a position at EW.
Before peer-review (a difficult task for things the author thinks may be fundamentally trivial) a simpler refuting paper uploaded on arXiv or viXra would be a good start.
As a side note, I really like my current job, and would have no interest in moving to EW.
What value is there to peer review? That's funny. Cause I thought that is what you're doing with TT? Or could it be that you're cherry picking where you fight your battles?
The issue is the value in me specifically writing such a paper, particularly when others have already done more thorough critiques.
And yes, I pick my battles to be ones where I know I have data to support my points. Especially in this section of the forum, I try to stick to things where I thoroughly know what I am talking about, because there are too many people in this section who try to engage in discussions about things they don't have the background for. (Note I am referring to people who act as if they know what they are talking about when they clearly don't. People who admit they don't have the background and want someone to review their ideas are different i.e. they are trying to learn.)
I agree. But this is not about my knowledge or experience. This is about yours, Mr. Sawyer and Dr. White.
So, then It would be fair to say that you really don't have the background or experience of people like Roger Sawyer and Harold White (but please do tell if you believe yours is on par). So I'd question what kind of weight you'd have in questioning Dr. Whites results. Do you work for an institution on par with EW? Because I think you'd agree they do not employ just any charlatan off the street. I will repeat what I said in a different post:
Publish something. Get something tangible out there or you're basically just the same person that you described in your post above.
You really should take your posts to a different thread. -
#1841 by Rodal on 23 Sep, 2017 23:03
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...
Thank you for taking your time to thoroughly answer
Edit: This is what I mean when I say the EM vacuum is degenerate and conformal. "Any" spectral energy density where ρ(ω) ~ ω3 is a solution. As such, there are an infinite number of possible EM vacuum states. The vacuum state is not unique in QED. -
#1842 by spupeng7 on 24 Sep, 2017 02:07
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1. considering speed of effects acting locally at an idealized point the problem is mathematically not well-posed because there is no distance to travel so there is no well-posed speed dx/dt as a derivative. Yes the time of propagation dt is zero, hence instantaneous instead of infinitesimal, but dx/dt is undefinable because dx is also zero (not infinitesimal). I think that since the speed of propagation problem is not mathematically well-posed or physically well posed (can something be much smaller than a Planck length? can something be just a point) then the idealization to a point is not subject to experimental analysis.
True. Considering gravitational force equivalent with centripetal force at orbit the tidal effects i.e. mass distribution changes travelling speed c are negligible....
Thanks, I need some time to carefully read his paper. Extended bodies (as opposed to particles) should not exactly follow geodesics as shown in a remarkable series of papers by Dixon in the 1970's (for example http://rspa.royalsocietypublishing.org/content/314/1519/499.short , http://rspa.royalsocietypublishing.org/content/319/1539/509.short
It's apparently instantaneous at static field. The experimentalist Kopeikin: https://arxiv.org/pdf/gr-qc/0507001
That's because of no changes propagates - bodies just follow geodesics of spacetime.
http://rsta.royalsocietypublishing.org/content/277/1264/59.short). Only point particles follow geodesics.
2. for finite bodies, the speed of propagation of gravitational field disturbances from one material point to another material point (or from one point in space to another point in space) is c (or less than c when involving particles having mass). Never instantaneous between different points [except entanglement]. This applies to mass distribution changes. As confirmed by experiments [nothing instantaneous except entanglement]. I like the term "mass distribution changes"
Thanks
Rodal,
the notion of distance assumed in "Never instantaneous between different points [except entanglement]." is necessarily a Euclidian notion. Is it not?
How is the concept of simultaneity between points separated by ict not superior to this clumsy and complicated frame that you insist on using to interpret the transfer of energy? -
#1843 by spupeng7 on 24 Sep, 2017 02:16
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"Why are you here?"
is a excellent question related to the anthropic principle!
Maybe because the universe exists as it is and we are interested in its underlying principles and the EM-Drive.
That's obvious 
I really feel like this silly copper can is our Monolith.
Maybe it is our Rosetta stone, guiding us toward a better understanding of remotely acting forces. -
#1844 by Mark7777777 on 24 Sep, 2017 02:20
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Here are the results of https://strawpoll.com/yp8y56rc
"If I had to guess, an Emdrive produces thrust because of:
Noise or experimental error
Radiation pressure
Vacuum energy
Quantised inertia
Photon leakage
Mach effect
Warp field
A combination of one or more of the above
Other
It doesn't produce thrust"
The poll is still open for those that haven't submitted and want to.
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#1845 by Rodal on 24 Sep, 2017 02:31
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Comment on the paper by Kopeikin:
It's apparently instantaneous at static field. The experimentalist Kopeikin: https://arxiv.org/pdf/gr-qc/0507001
A correction: Please cite experimental evidence for your assertion above that "Gravitation is apparently instantaneous"
A correction: information of the changes in the distribution of masses trvavels at speed c. Gravitation is apparently instantaneous. Similarly inertia seems to get space contact at its position, hence in respect of surrounding masses inertia seems to be instantaneous too. Naturally, those phenomena are common....
Not a precise statement of Einstein's assumption. Instead Einstein assumed the equivalence principle.
Nothing except that mass resists acceleration instantly. GR assumes that mass resists acceleration because it is mass, which is a circular argument based on faith. This could be wrong, if no other explanation for emdrive thrust is found, while it continues to be verified, then GR is an incomplete description of mechanics.
"we [...] assume the complete physical equivalence of a gravitational field and a corresponding
acceleration of the reference system."
Not a circular argument.
Please let us know what experiments do you know of that have found a difference between gravitational mass and inertial mass.
http://iopscience.iop.org/article/10.1088/0264-9381/29/18/180301/meta
https://en.wikipedia.org/wiki/Equivalence_principle#Tests_of_the_weak_equivalence_principle
Please let us know what experiments you know of that have revealed a Machian effect not present in Einstein's General Relativity.
You also state: "mass resists acceleration instantly" please let us know what experiments do you know of that prove that mass resists acceleration instantly (superluminally : much faster than the speed of light) while gravitation travels at the speed of light (not instantly)
That's because of no changes propagates - bodies just follow geodesics of spacetime.
1.) There also was Tom van Flandern and the "speed of gravity" Jupiter experiment.
van Flandern:
http://www.gravitywarpdrive.com/Speed_of_Gravity.htm
http://www.sciencedirect.com/science/article/pii/S0375960198006501?via%3Dihub
2.) Just like the Newtonian case, in PPN you use _coordinates of date_, not retarded, in doing (https://en.wikipedia.org/wiki/Parameterized_post-Newtonian_formalism) PPN gravity., van Flandern was found incorrect by Carlip. The arguments by Carlip are convincing (to me):
https://arxiv.org/abs/gr-qc/9909087
In any case (in one of the above links) Van Flandern admits "research support for promising but unpopular alternative ideas in astronomy" -- admits that the idea is unpopular.
3.) There was an attempt that involved the VLBI (https://en.wikipedia.org/wiki/Very-long-baseline_interferometry) measurement of the gravitational lensing (deflection) from Jupiter, and whether that could be used to measure the "speed of gravity"
https://arxiv.org/abs/astro-ph/0206266
https://arxiv.org/pdf/gr-qc/0310059.pdf
https://arxiv.org/abs/gr-qc/0310065
https://arxiv.org/abs/astro-ph/0303346
https://arxiv.org/abs/astro-ph/0304006
https://arxiv.org/abs/astro-ph/0308343
https://arxiv.org/abs/astro-ph/0311063
https://arxiv.org/abs/gr-qc/0403060
https://arxiv.org/abs/astro-ph/0412401
https://arxiv.org/abs/gr-qc/0510048
https://arxiv.org/abs/gr-qc/0510056
https://arxiv.org/abs/gr-qc/0510077
Conclusions:
1) in view of the above papers it appears to me that Kopeikin's views on the "speed of gravity" as reflected by the paper you are quoting were not proven correct. I will withhold any further opinion on this controversy in this thread, as debating this will take us too far away from "EM Drive Developments - related to space flight applications." We have enough controversy already with the EM Drive itself
Readers interested in this controversy can follow this further here: https://en.wikipedia.org/wiki/Speed_of_gravity#Possible_experimental_measurements
I quote:QuoteHowever, Kopeikin and Fomalont continue to vigorously argue their case and the means of presenting their result at the press-conference of AAS that was offered after the peer review of the results of the Jovian experiment had been done by the experts of the AAS scientific organizing committee. In later publication by Kopeikin and Fomalont, which uses a bi-metric formalism that splits the space-time null cone in two – one for gravity and another one for light, the authors claimed that Asada's claim was theoretically unsound.[21] The two null cones overlap in general relativity, which makes tracking the speed-of-gravity effects difficult and requires a special mathematical technique of gravitational retarded potentials, which was worked out by Kopeikin and co-authors[22][23] but was never properly employed by Asada and/or the other critics.
2) Yes, in the PPN coordinate system everything appears instantaneous. Recall that PPN is a scheme to compare Newtonian and Einsteinian gravity in the limit in which the gravitational field is weak and generated by objects moving slowly compared to the speed of light. Recall that in Newtonian gravity, the speed of gravity is instantaneous.
3) But of course, how it appears in a PPN coordinate system is a separate issue from the question of the actual physical speed of gravitational waves. -
#1846 by meberbs on 24 Sep, 2017 07:48
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I agree. But this is not about my knowledge or experience. This is about yours, Mr. Sawyer and Dr. White.
I am going to pretend you didn't mention Shawyer, since he has demonstrated repeatedly that he has trouble with basic physics concepts like force balances.
So, then It would be fair to say that you really don't have the background or experience of people like Roger Sawyer and Harold White (but please do tell if you believe yours is on par).
I can't say that I have the same background as Dr. White, but I have plenty of relevant background. You seem to going down a path of argument from authority with this though, you don't necessarily need a Phd to find flaws in an experiment run by a Phd.Do you work for an institution on par with EW?
Depends on what you mean by institution and what criteria you are judging on. I mentioned no interest in moving to EW and there is a reason for that. In my opinion, the place where I work is much better.Publish something. Get something tangible out there or you're basically just the same person that you described in your post above.
Publishing something does not differentiate between the types of people I described.
You still seem to not have understood anything I said. Other people have already written critiques of the Eagleworks experiments. Remember that this discussion started with something from you:I for one would like to see meberbs publish his assertions on his interpretation of Dr. Harold White's papers. I'm guessing getting past the peer review process would be a better way to be vindicated than getting into endless argument loops here. Maybe he could score a position at EW.
I have not made any assertions recently about those experiments. I have no idea why you are specifically insisting I publish something on those experiments. If you think publishing something should be a discriminator for who should be posting here why don't you publish a rebuttal to the criticisms that others have made about Dr. White's experiments? -
#1847 by Mulletron on 24 Sep, 2017 12:23
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This is a pretty recent study of the speed of gravity using Ligo data. It isn't constrained to exactly c just yet. Instantaneous propagation is outside their bounds.
https://arxiv.org/abs/1707.06101
A well written article about this subject:
https://www.forbes.com/sites/startswithabang/2016/04/28/why-does-gravity-move-at-the-speed-of-light/?s=trending#fbd41ca62110 -
#1848 by Eusa on 24 Sep, 2017 12:56
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Gravitational waves signal just for mass distribution changes and propagates at speed c. When static curvature of spacetime considered it seems to be instantaneous gravity signal but there is no signal indeed.
These principles are important when trying understand propellantless thrusters. When something (mass field?) accelerate drive, drive must accelerate back and finally some objects accelerates keeping sum of momentum the same everywhere under affecting phenomenon...
Before Jamies results from spheroidical cavity I think the emdrive effect can be a temporal magnetic field reaction. -
#1849 by Mulletron on 24 Sep, 2017 13:14
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Comment on the paper by Kopeikin:
It's apparently instantaneous at static field. The experimentalist Kopeikin: https://arxiv.org/pdf/gr-qc/0507001
A correction: Please cite experimental evidence for your assertion above that "Gravitation is apparently instantaneous"
A correction: information of the changes in the distribution of masses trvavels at speed c. Gravitation is apparently instantaneous. Similarly inertia seems to get space contact at its position, hence in respect of surrounding masses inertia seems to be instantaneous too. Naturally, those phenomena are common....
Not a precise statement of Einstein's assumption. Instead Einstein assumed the equivalence principle.
Nothing except that mass resists acceleration instantly. GR assumes that mass resists acceleration because it is mass, which is a circular argument based on faith. This could be wrong, if no other explanation for emdrive thrust is found, while it continues to be verified, then GR is an incomplete description of mechanics.
"we [...] assume the complete physical equivalence of a gravitational field and a corresponding
acceleration of the reference system."
Not a circular argument.
Please let us know what experiments do you know of that have found a difference between gravitational mass and inertial mass.
http://iopscience.iop.org/article/10.1088/0264-9381/29/18/180301/meta
https://en.wikipedia.org/wiki/Equivalence_principle#Tests_of_the_weak_equivalence_principle
Please let us know what experiments you know of that have revealed a Machian effect not present in Einstein's General Relativity.
You also state: "mass resists acceleration instantly" please let us know what experiments do you know of that prove that mass resists acceleration instantly (superluminally : much faster than the speed of light) while gravitation travels at the speed of light (not instantly)
That's because of no changes propagates - bodies just follow geodesics of spacetime.
1.) There also was Tom van Flandern and the "speed of gravity" Jupiter experiment.
van Flandern:
http://www.gravitywarpdrive.com/Speed_of_Gravity.htm
...
Lots of "useful fiction" on that site; useful if you don't actually read (besides for entertainment purposes) or believe any of it. I mostly just look at the pictures. Intriguing. Bunk technical descriptions and meaningless woo aside; I wonder how well that fictional wedge would do at interfering shear waves if the large end wasn't a perfect reflector? -
#1850 by ThinkerX on 24 Sep, 2017 19:25
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Gravitational waves signal just for mass distribution changes and propagates at speed c. When static curvature of spacetime considered it seems to be instantaneous gravity signal but there is no signal indeed.
These principles are important when trying understand propellantless thrusters. When something (mass field?) accelerate drive, drive must accelerate back and finally some objects accelerates keeping sum of momentum the same everywhere under affecting phenomenon...
Before Jamies results from spheroidical cavity I think the emdrive effect can be a temporal magnetic field reaction.
I have wondered a time or three if the EM Drives 'movement' isn't the result of a sort of 'magnetic trick,' perhaps something roughly akin to a rail-gun or magnetically levitating a coin. I seem to remember Shell saying her experiments indicated something like this a few weeks ago. I have no clue as to whether or not this mechanism would move the device in space at 'EM Drive speeds.'
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#1851 by Mulletron on 24 Sep, 2017 20:08
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Interesting activity happening at the corner. Imagine two (or many) of such shear waves constructively interfering at a point.
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#1852 by spupeng7 on 25 Sep, 2017 01:23
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(...)
2. for finite bodies, the speed of propagation of gravitational field disturbances from one material point to another material point (or from one point in space to another point in space) is c (or less than c when involving particles having mass). Never instantaneous between different points [except entanglement]. This applies to mass distribution changes. As confirmed by experiments [nothing instantaneous except entanglement]. I like the term "mass distribution changes" Thanks
Rodal, you argue that GR is established almost beyond question but then write about entanglement being an instantaneous interaction, as if there were no contradiction between these interpretations. You write about distance between points at a moment of time as if that moment was definable outside of complex time but that definition requires a preferred perspective, without which the simultaneity breaks down.
What path does the measure, of distance between the points at which particles which are entangled, take. "[nothing instantaneous except entanglement]" instantaneous from whose perspective?
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#1853 by OnlyMe on 25 Sep, 2017 04:42
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(...)
2. for finite bodies, the speed of propagation of gravitational field disturbances from one material point to another material point (or from one point in space to another point in space) is c (or less than c when involving particles having mass). Never instantaneous between different points [except entanglement]. This applies to mass distribution changes. As confirmed by experiments [nothing instantaneous except entanglement]. I like the term "mass distribution changes" Thanks
Rodal, you argue that GR is established almost beyond question but then write about entanglement being an instantaneous interaction, as if there were no contradiction between these interpretations. You write about distance between points at a moment of time as if that moment was definable outside of complex time but that definition requires a preferred perspective, without which the simultaneity breaks down.
What path does the measure, of distance between the points at which particles which are entangled, take. "[nothing instantaneous except entanglement]" instantaneous from whose perspective?
GR is a very good description of the dynamics of gravitation... With some caveats for the necessity of adding dark matter and energy into the mix. To adjust for otherwise unexplained observations.
The velocity limitations for massive and massless particles, is well defined. Massless photons travel at the speed of light and all massive particles or objects travel at velocities less than the speed of light.
No information travels between entangled particles. The properties of an entangled pair of particles are established at their instance of origin. When you later measure some property of one of the pair, nothing changes about its counterpart, other than because they are entangled you then know something about the unmeasured particle. Again no information travels between the two. Because they are entangled when you measure one you instantly know something about the other. That all. -
#1854 by Stormbringer on 25 Sep, 2017 04:53
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https://phys.org/news/2017-09-gravitational-oscillate-neutrinos.html
https://www.sciencealert.com/quantum-flashes-could-be-what-finally-links-relativity-and-quantum-theory
We do not know what gravity actually is yet.
GR works but describes gravity as the result of mass or energy deforming space time with no recourse to quanticised particles like gravitons.
Sometimes a model that describes a thing isn't really the thing or really how the thing actually works. There were fantastic mechanical models that imitated the orbital positions of the known planets, the moon the sun and the stars. you could use them to predict where these celestial objects would be in advance and backtrack them to show where they were in the past but they certainly bore no other relationship to reality as came to be known. They used all sorts of improbable relationships and components to imitate the way the sky appeared to an observer on earth's surface,-even to explain retrogrades. But they certainly would not support the equations that came to be known as celestial and orbital mechanics. some of these were made even before the geocentric view of the universe was discredited. Thus they were based on the idea that all celestial objects orbited the earth. their apriori assumptions were fundamentally incorrect but they were jiggered until they matched observation. they were models that produced correct predictions, matched observations but were otherwise completely wrong.
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#1855 by RERT on 25 Sep, 2017 10:13
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It is truly a small world. The WG Dixon Dr. Rodal cited last page was my undergraduate director of studies. He was the person I referred to ages ago who said the he had chosen the (fearsomely complicated) study of the elastodynamics of extended bodies in GR in order to avoid the conceptual minefield which was Quantum Mechanics. He never lectured to me himself.
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#1856 by JonathanD on 25 Sep, 2017 13:54
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We do not know what gravity actually is yet.
Well, glad I"m not the only one! -
#1857 by ThatOtherGuy on 25 Sep, 2017 15:07
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I found this 2 Channel USB Solid State Relay Module for $60 that looks like it will be a good solution:
https://numato.com/product/2-channel-usb-solid-state-relay-module
Mono... did you see these ?
http://relaypros.com/Relay/Relay/USB_Relay_Controller
there's stuff from "NI" too, but I suspect they won't be cheap
http://www.ni.com/en-us/support/model.usb-6525.html
(edit)
check out these too
http://denkovi.com/usb-relay-board-four-channels-for-home-automation
(example http://denkovi.com/SoftwareExamples/usb_4_8_labview/USB_4_8_RelayDemoVI.jpg )
HTH
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#1858 by Monomorphic on 25 Sep, 2017 16:25
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Mono... did you see these ?
http://relaypros.com/Relay/Relay/USB_Relay_Controller
there's stuff from "NI" too, but I suspect they won't be cheap
http://www.ni.com/en-us/support/model.usb-6525.html
(edit)
check out these too
http://denkovi.com/usb-relay-board-four-channels-for-home-automation
(example http://denkovi.com/SoftwareExamples/usb_4_8_labview/USB_4_8_RelayDemoVI.jpg )
HTH
Those relay switches are electromechanical. They use a small EM coil to make contact. I chose solid-state to avoid putting EM coils on the torsional pendulum. Of course the NI USB-6525 would be nice, but it is overkill and expensive. I ordered the numato solid-state relay and it gets here Wednesday. -
#1859 by PotomacNeuron on 25 Sep, 2017 16:40
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Mono... did you see these ?
http://relaypros.com/Relay/Relay/USB_Relay_Controller
there's stuff from "NI" too, but I suspect they won't be cheap
http://www.ni.com/en-us/support/model.usb-6525.html
(edit)
check out these too
http://denkovi.com/usb-relay-board-four-channels-for-home-automation
(example http://denkovi.com/SoftwareExamples/usb_4_8_labview/USB_4_8_RelayDemoVI.jpg )
HTH
Those relay switches are electromechanical. They use a small EM coil to make contact. I chose solid-state to avoid putting EM coils on the torsional pendulum. Of course the NI USB-6525 would be nice, but it is overkill and expensive. I ordered the numato solid-state relay and it gets here Wednesday.
I recall that when I carried out my experiment (published in the grounding loop paper), I designed and made a light driven solid state relay without *any* ferromagnetic material in it. Note that most cheap resistors, capacitors, LEDs and photo-diodes on the market have iron leads.
Thanks
That's obvious 